GPR3, GPR6, and GPR12 as novel molecular targets: their biological functions and interaction with cannabidiol.

Posted on June 27, 2018 by David

“The G protein-coupled receptors 3, 6, and 12 (GPR3, GPR6, and GPR12) comprise a family of closely related orphan receptors with no confirmed endogenous ligands. These receptors are constitutively active and capable of signaling through G protein-mediated and non-G protein-mediated mechanisms. These orphan receptors have previously been reported to play important roles in many normal physiological functions and to be involved in a variety of pathological conditions.

Although they are orphans, GPR3, GPR6, and GPR12 are phylogenetically most closely related to the cannabinoid receptors. Using β-arrestin2 recruitment and cAMP accumulation assays, we recently found that the nonpsychoactive phytocannabinoid cannabidiol (CBD) is an inverse agonist for GPR3, GPR6, and GPR12.

This discovery highlights these orphan receptors as potential new molecular targets for CBD, provides novel mechanisms of action, and suggests new therapeutic uses of CBD for illnesses such as Alzheimer’s disease, Parkinson’s disease, cancer, and infertility. Furthermore, identification of CBD as a new inverse agonist for GPR3, GPR6, and GPR12 provides the initial chemical scaffolds upon which potent and efficacious agents acting on these receptors can be developed, with the goal of developing chemical tools for studying these orphan receptors and ultimately new therapeutic agents.”

https://www.ncbi.nlm.nih.gov/pubmed/29941868

https://www.nature.com/articles/s41401-018-0031-9

Endocannabinoid and Muscarinic Signaling Crosstalk in the 3xTg-AD Mouse Model of Alzheimer’s Disease.

Posted on June 9, 2018 by David

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“The endocannabinoid system, which modulates emotional learning and memory through CB1 receptors, has been found to be deregulated in Alzheimer’s disease (AD).

AD is characterized by a progressive decline in memory associated with selective impairment of cholinergic neurotransmission. The functional interplay of endocannabinoid and muscarinic signaling was analyzed in seven-month-old 3xTg-AD mice following the evaluation of learning and memory of an aversive stimulus.

The subchronic (seven days) stimulation of the endocannabinoid system following repeated WIN55,212-2 (1 mg/kg) or JZL184 (8 mg/kg) administration induced a CB1 receptor downregulation and CB1-mediated signaling desensitization, normalizing acquisition latencies to control levels. However, the observed modulation of cholinergic neurotransmission in limbic areas did not modify learning and memory outcomes.

A CB1 receptor-mediated decrease of GABAergic tone in the basolateral amygdala may be controlling the limbic component of learning and memory in 3xTg-AD mice. CB1 receptor desensitization may be a plausible strategy to improve behavior alterations associated with genetic risk factors for developing AD.”

https://www.ncbi.nlm.nih.gov/pubmed/29865071

https://content.iospress.com/articles/journal-of-alzheimers-disease/jad180137

Cannabinoid Receptor 2-Deficiency Ameliorates Disease Symptoms in a Mouse Model with Alzheimer’s Disease-Like Pathology.

Posted on June 6, 2018 by David

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“It is widely accepted that the endocannabinoid system (ECS) is a modulator of neuroinflammation associated with neurodegenerative disorders, including Alzheimer’s disease (AD).

Thus, expression of the cannabinoid receptor 2 (CB2) is induced in plaque-associated microglia and astrocytes in brain tissues from AD patients and in genetic mouse models expressing pathogenic variants of the amyloid precursor protein (APP).

However, the exact mechanism of CB2 signaling in this mouse model remains elusive, because the genetic deletion of CB2 and the pharmacological activation of CB2 both reduced neuroinflammation.

Here, we demonstrate that CB2 deletion also improved cognitive and learning deficits in APP/PS1*CB2-/- mice. This was accompanied by reduced neuronal loss and decreased plaque levels and coincided with increased expression of Aβ degrading enzymes. Interestingly, plaque-associated microglia in APP/PS1*CB2-/- mice showed a less activated morphology, while plaques were smaller and more condensed than in APP/PS1 mice.

Taken together, these results indicate a beneficial effect of CB2-deficiency in APP transgenic mice. CB2 appears to be part of a protective system that may be detrimental when engaged continuously.”

https://www.ncbi.nlm.nih.gov/pubmed/29865078

https://content.iospress.com/articles/journal-of-alzheimers-disease/jad180230

The biomedical challenge of neurodegenerative disorders: an opportunity for cannabinoid-based therapies to improve on the poor current therapeutic outcomes.

Posted on June 2, 2018 by David

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“At the beginning of the 21st century, the therapeutic management of neurodegenerative disorders remains a major biomedical challenge, particularly given the worldwide aging of the population over the past 50 years that is expected to continue in the forthcoming years.

This review will focus on the promise of cannabinoid based therapies to address this challenge.

Such promise is based on the broad neuroprotective profile of cannabinoids, which may cooperate to combat excitotoxicity, oxidative stress, glia-driven inflammation and protein aggregation.

Such effects may be produced by the activity of cannabinoids through their canonical targets (e.g. cannabinoid receptors, endocannabinoid enzymes) but also, via non-canonical elements and activities in distinct cell types critical for cell survival or neuronal replacement (e.g. neurons, glia, neural precursor cells).

Ultimately, the therapeutic events driven by endocannabinoid signalling reflect the activity of an endogenous system that regulates the preservation, rescue, repair and replacement of neurons and glia.”

https://www.ncbi.nlm.nih.gov/pubmed/29856067

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14382

Cannabinoid CB2 receptors in the mouse brain: relevance for Alzheimer’s disease.

Posted on May 30, 2018 by David

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“Because of their low levels of expression and the inadequacy of current research tools, CB₂ cannabinoid receptors (CB₂R) have been difficult to study, particularly in the brain. This receptor is especially relevant in the context of neuroinflammation, so novel tools are needed to unveil its pathophysiological role(s).

METHODS:

We have generated a transgenic mouse model in which the expression of enhanced green fluorescent protein (EGFP) is under the control of the cnr2 gene promoter through the insertion of an Internal Ribosomal Entry Site followed by the EGFP coding region immediately 3′ of the cnr2 gene and crossed these mice with mice expressing five familial Alzheimer’s disease (AD) mutations (5xFAD).

RESULTS:

Expression of EGFP in control mice was below the level of detection in all regions of the central nervous system (CNS) that we examined. CB₂R-dependent-EGFP expression was detected in the CNS of 3-month-old AD mice in areas of intense inflammation and amyloid deposition; expression was coincident with the appearance of plaques in the cortex, hippocampus, brain stem, and thalamus. The expression of EGFP increased as a function of plaque formation and subsequent microgliosis and was restricted to microglial cells located in close proximity to neuritic plaques. AD mice with CB₂R deletion exhibited decreased neuritic plaques with no changes in IL1β expression.

CONCLUSIONS:

Using a novel reporter mouse line, we found no evidence for CB₂R expression in the healthy CNS but clear up-regulation in the context of amyloid-triggered neuroinflammation. Data from CB₂R null mice indicate that they play a complex role in the response to plaque formation.”

https://www.ncbi.nlm.nih.gov/pubmed/29793509

https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-018-1174-9

An overview of the cannabinoid type 2 receptor system and its therapeutic potential.

Posted on May 30, 2018 by David

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“This narrative review summarizes recent insights into the role of the cannabinoid type 2 (CB2) receptor as potential therapeutic target in neuropathic pain and neurodegenerative conditions.

RECENT FINDINGS:

The cannabinoid system continues to receive attention as a therapeutic target. The CB2 receptor is primarily expressed on glial cells only when there is active inflammation and appears to be devoid of undesired psychotropic effects or addiction liability. The CB2 receptor has been shown to have potential as a therapeutic target in models of diseases with limited or no currently approved therapies, such as neuropathic pain and neurodegenerative conditions such as Alzheimer’s disease.

SUMMARY:

The functional involvement of CB2 receptor in neuropathic pain and other neuroinflammatory diseases highlights the potential therapeutic role of drugs acting at the CB2 receptor.”

https://www.ncbi.nlm.nih.gov/pubmed/29794855

https://insights.ovid.com/crossref?an=00001503-900000000-98981

Is Cannabidiol a Promising Substance for New Drug Development? A Review of its Potential Therapeutic Applications.

Posted on May 19, 2018 by David

Critical Reviewsâ¢ in Eukaryotic Gene Expression

“The pharmacological importance of cannabidiol (CBD) has been in study for several years.

CBD is the major nonpsychoactive constituent of plant Cannabis sativa and its administration is associated with reduced side effects.

Currently, CBD is undergoing a lot of research which suggests that it has no addictive effects, good safety profile and has exhibited powerful therapeutic potential in several vital areas.

It has wide spectrum of action because it acts through endocannabinoid receptors; CB1 and CB2 and it also acts on other receptors, such as GPR18, GPR55, GPR 119, 5HT1A, and TRPV2.

This indicates its therapeutic value for numerous medical conditions because of its neuroprotective and immunomodulatory properties.

Potential therapeutic applications of CBD include, analgesic, anti-inflammatory, anxiolytic, anti-arthritic, anti-depressant, anti-Alzheimer disease, anti-ischemic, neuroprotective, and anti-fibrotic.

More promising areas appear to include diabetes and cancer where CBD exhibits lesser side effects and more therapeutic benefits as compared to recent available medical therapies.

Hence, CBD is a promising substance for the development of new drug. However further research and clinical studies are required to explore its complete potential.”

https://www.ncbi.nlm.nih.gov/pubmed/29773016

http://www.dl.begellhouse.com/journals/6dbf508d3b17c437,642ad759707fc517,35856ff546e47ff9.html

Review of the neurological benefits of phytocannabinoids.

Posted on May 18, 2018 by David

“Numerous physical, psychological, and emotional benefits have been attributed to marijuana since its first reported use in 2,600 BC in a Chinese pharmacopoeia. The phytocannabinoids, cannabidiol (CBD), and delta-9-tetrahydrocannabinol (Δ9-THC) are the most studied extracts from cannabis sativa subspecies hemp and marijuana. CBD and Δ9-THC interact uniquely with the endocannabinoid system (ECS). Through direct and indirect actions, intrinsic endocannabinoids and plant-based phytocannabinoids modulate and influence a variety of physiological systems influenced by the ECS.